Claims
- 1. A method of making a high strength powder metallurgical component comprising the steps of:
- (a) providing an iron-based power composition comprising iron particles having an outer coating of a thermoplastic material, the thermoplastic material constituting from about 0.001% to about 15% by weight of the iron particles as coated;
- (b) compacting the composition in a die at a temperature above the glass transition temperature of the thermoplastic; and
- (c) separately heating the component at a temperature that is at least as high as the compaction temperature, up to about 800.degree. F.
- 2. The method according to claim 1 wherein the compacted component is allowed to cool to a temperature at least as low as the glass transition temperature of the thermoplastic prior to said heating step.
- 3. The method according to claim 2 wherein the thermoplastic material is selected from the group consisting of polyphenylene ethers and polyetherimides and wherein the thermoplastic material constitutes about 0.4-2% by weight of the coated materials.
- 4. The method according to claim 3 wherein said heating step is conducted at a temperature of from about 450.degree.-800.degree. F.
- 5. The method of claim 3 wherein the compaction step is conducted at a pressure of 30-60 tsi and a temperature in the range of about 50-150.degree. F. above the glass transition temperature of the thermoplastic material.
- 6. The method according to claim 5 wherein the iron particles have a weight average particle size of about 10-200 microns and the heating step is conducted at a temperature of about 450.degree.-800.degree. F.
- 7. The method according to claim 1 wherein the iron core particles have a first, inner coating of an insulative inorganic material.
- 8. The method according to claim 6 wherein the iron core particles have a first, inner coating of an insulative inorganic material.
- 9. The method according to claim 1 wherein the compaction step comprises compression molding.
- 10. The method according to claim 1 wherein the compaction step comprises an injection molding process and wherein the thermoplastic material constitutes at least about 8% by weight of the coated particles.
- 11. The product produced by the method of claim 1.
- 12. The product produced by the method of claim 2.
- 13. The product produced by the method of claim 3.
- 14. The product produced by the method of claim 4.
- 15. The product produced by the method of claim 7.
- 16. A method of making a high strength powder metallurgical component comprising the steps of:
- (a) providing an iron/thermoplastic powder composition comprising iron particles admixed with a thermoplastic material in particulate form, the thermoplastic material constituting from about 0.001% to about 15% by weight of the composition;
- (b) compacting the composition in a die at a temperature above the glass transition temperature of the thermoplastic; and
- (c) separately heating the component to a temperature that is at least as high as the composition temperature, up to about 800.degree. F.
- 17. The method according to claim 16 wherein the compacted component is allowed to cool to a temperature at least as low as the glass transition temperature of the thermoplastic prior to said heating step.
- 18. The method according to claim 17 wherein the thermoplastic material is selected from the group consisting of polyphenylene ethers and polytherimides, and wherein the thermoplastic material constitutes about 0.4-2% by weight of the composition.
- 19. The method according to claim 18 wherein said heating step is conducted at a temperature of about 450.degree.-800.degree. F.
- 20. The method of claim 18 wherein the compaction step is conducted at a pressure of 30-60 tsi and a temperature in the range of about 150.degree.-150.degree. F. above the glass transition temperature of the thermoplastic material.
- 21. The method according to claim 20 wherein the iron particles have a weight average particle size of about 10-200 microns, and the heating step is conducted at a temperature of about 450.degree.-800.degree. F.
- 22. The method according to claim 16 wherein the iron/thermoplastic powder composition is made by a method comprising the steps of (a) forming a dry admixture of the iron particles and particles of thermoplastic material; (b) wetting the dry admixture with a solvent for the thermoplastic material; and (c) removing the solvent.
Parent Case Info
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 7/770,648, filed Oct. 3, 1991, now abandoned.
US Referenced Citations (12)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
770648 |
Oct 1991 |
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